Wastewater is any water that has been adversely affected in quality by anthropogenic influence.
It comprises:
• liquid waste discharged by domestic residences,
• commercial properties,
• industry, and/or agriculture
• and can encompass a wide range of potential contaminants and concentrations.
In the most common usage, it refers to the municipal wastewater that contains a broad spectrum of contaminants resulting from the mixing of wastewaters from different sources.
Wastewater constituents Water 95%
Pathogens such as bacteria, viruses, prions and parasitic worms.
Non-pathogenic bacteria (> 100,000 / ml for sewage)
Organic particles such as faeces, hairs, food, vomit, paper fibers, plant material, humus, etc.
Soluble organic material such as urea, fruit sugars, soluble proteins, drugs, pharmaceuticals, etc.
Inorganic particles such as sand, grit, metal particles, ceramics, etc.
Soluble inorganic material such as ammonia, road-salt, sea-salt, cyanide, hydrogen sulfide, thiocyanates, thiosulfates, etc.
Animals such as protozoa, insects, arthropods, small fish, etc.
Macro-solids such as sanitary napkins, nappies/diapers, condoms, needles, children's toys, dead pets, body parts, etc.
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Gases such as hydrogen sulfide, carbon dioxide, methane, etc.
Emulsions such as paints, adhesives, mayonnaise, hair colorants, emulsified oils, etc.
Toxins such as pesticides, poisons, herbicides, etc.
BOD
Biochemical oxygen demand and chemical oxygen d
Any oxidizable material present in a natural waterway or in an industrial wastewater will be oxidized both by biochemical (bacterial) or chemical processes. As a result the oxygen content of the water will be decreased. Basic reaction for biochemic
oxidation may be written as:
Oxidizable material + bacteria + nutrient + O CO
N – compunds - NH4+, NO
P - compounds - PO43-, total phosphorus TOC – total organic carbon
DOC - dissolved organic carbon VOC – volatile organic compounds
AOX - adsorbable organohalogens eg. organically bound halogens EOX - extractable organic halogens.
Which parameters should be analyzed?
Legislation (monitoring)
- European Union Council Directive 91/271/EEC on Urban Waste Water Treatment
- National level, for example „
kord” (http://www.riigiteataja.ee/ert/act.jsp?id=13136367 - Local authorities
- Lab experience (research)
2 Sampling
Siiri Velling (Tartu Ülikool), 2011
Gases such as hydrogen sulfide, carbon dioxide, methane, etc.
Emulsions such as paints, adhesives, mayonnaise, hair colorants, emulsified Toxins such as pesticides, poisons, herbicides, etc.
and COD
Biochemical oxygen demand and chemical oxygen demand
Any oxidizable material present in a natural waterway or in an industrial wastewater will be oxidized both by biochemical (bacterial) or chemical processes. As a result the oxygen content of the water will be decreased. Basic reaction for biochemic
oxidation may be written as:
Oxidizable material + bacteria + nutrient + O2→
adsorbable organohalogens eg. organically bound halogens extractable organic halogens.
Which parameters should be analyzed?
Council Directive 91/271/EEC on Urban Waste Water National level, for example „Heitvee veekogusse või pinnasesse juhtimise
http://www.riigiteataja.ee/ert/act.jsp?id=13136367) (research).
6 Emulsions such as paints, adhesives, mayonnaise, hair colorants, emulsified
Any oxidizable material present in a natural waterway or in an industrial wastewater will be oxidized both by biochemical (bacterial) or chemical processes. As a result the oxygen content of the water will be decreased. Basic reaction for biochemical
3 or SO4
Council Directive 91/271/EEC on Urban Waste Water Heitvee veekogusse või pinnasesse juhtimise
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Sampling is an essential part of representative part of analyzing
Sample collection should fulfill the goals of study as well the sample must correspond to the requirements of analysis.
General sample collection problems:
• change in the properties of an object in
• heterogenous, complicated systems
• low concentrations, lots of parameters to study Sample collection “musts”:
• The representative part of object remains unchainged
• Correspondence of sample properties to
• No changes in sample properties during sample collection, transport and/or conservation
What has to be considered?
specifics of analysis sampling frequency sampling place volume of a sample suitable containers
handling and preservation 2.1 Water samples
Individual and joint samples
o Individual – one time sample or a point sample o Individual samples unified into
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an essential part of analytical process and a sample must be a representative part of analyzing object.
Sample collection should fulfill the goals of study as well the sample must correspond to the requirements of analysis.
General sample collection problems:
change in the properties of an object in time or space heterogenous, complicated systems
low concentrations, lots of parameters to study Sample collection “musts”:
The representative part of object remains unchainged
Correspondence of sample properties to the requirements of analysis method No changes in sample properties during sample collection, transport and/or
What has to be considered?
specifics of analysis sampling frequency volume of a sample suitable containers
handling and preservation
Individual and joint samples
one time sample or a point sample
Individual samples unified into joint averaged samples
• Time proportional - collecting individual samples of a certain volume after known (assigned) time interval
• Discharge proportional - the time intervals are constant, but the volume of each sample is
proportional to the volume of discharge during the specific time interval
• Quantity proportional - the volume of each sample is constant, but
the temporal resolution of sampling is proportional to the discharge
• Event-controlled sampling - depends on the trigger signal.
7 must be a
Sample collection should fulfill the goals of study as well the sample must correspond
requirements of analysis method No changes in sample properties during sample collection, transport and/or
collecting individual samples of a certain volume after known
the time intervals are constant, but the volume of each sample is
proportional to the volume of discharge during the the volume of each n of sampling is
depends on the
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General guidelines 1. Location
- according to the pupose and characteristics of object - easy of approach
- allows to collect samples at the same place always - below 30 cm form the surface of water bodies - from the point of strong stream in rivers
(well-mixed area)
! Places that are not typical to the water body, should be avoided!
2. How often?
3. Sample volume
- amount of components to be analyzed - methods of analysis or study
4. Sample containers
- up to the components to be analyzed
- washed and labelled beforehand (in laboratory)
- should be rinsed with sample before final collecting of the sample (exept for the analy
- usually are filled to the brim 5. Water samplers
Automatic, portable, specific
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according to the pupose and characteristics of object easy of approach
allows to collect samples at the same place always below 30 cm form the surface of water bodies from the point of strong stream in rivers
mixed area)
Places that are not typical to the water body, should be avoided!
mount of components to be analyzed methods of analysis or study
Sample containers
up to the components to be analyzed
washed and labelled beforehand (in laboratory)
should be rinsed with sample before final collecting of the sample (exept for the analysis of oil products, oils, fats etc)
usually are filled to the brim.
Automatic, portable, specific
8 Places that are not typical to the water body, should be avoided!
should be rinsed with sample before final collecting of the sample
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9 General Considerations
Always fill sample containers - no air is left above the sample.
Use an appropriate container. For example polyethylene bottles should not be used for hydrocarbons, since adsorption on to the bottle's surface is likely to occur.
Glass containers are suitable for most determinations. Brown bottles should be used since this will reduce photosensitive reactions to a considerable extent.
Containers must be clean.
Samples should be kept at a temperature below that at the time of filling.
Cooling between 2 degrees and 5 degrees (ie. in melting ice, refrigerator or cool bag with ice packs) is adequate. It is not suitable for long-term storage.
Suspended matter, sediment, algae and other micro-organisms should be removed at the time of sampling by filtration or centrifuging or immediately on receipt at the laboratory. Filtration should not be carried out if the filter is likely to retain one or more of the constituents to be analysed.
Changes in sample composition may occur due to:
• consumption of certain constituents by bacteria, algae etc.,
• certain compounds being oxidised by the dissolved oxygen in the sample,
• precipitation from the liquid, eg. calcium carbonate, aluminium hydroxide,
• loss into the vapour phase,
• absorption of carbon dioxide from the air, changing the pH value,
• adsorption of metals and certain organic compounds on to the container's surface,
• depolymerisation of polymerised products and vice versa.
Sampling mistakes:
• Not enough partial samples
• By the sample collection procedure caused precipitation of particles,
evaporation of substances
• Changes of sample properties before analysis biodegradation, adsorption
Proper handling and preservation are very impotent to keep the sample content unchanged. The goal of specificd handling and preservation requirements are to remain the representative part of object unchainged for as long as possible or as needes.
Conservation and maintenance
• Samples should be as fresh as possible
• Preferably avoid the conservation of samples
• Non-conserved samples should be analyzed guring 24 hours from sample collection
• Conservation – to maintain the (specific) properties of samples and concentrations of ingredients for as long as possible (needed)
SPECIAL REQUIREMENTS
• Depending on the components to be analyzed in the sample or properties of sample
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10 Sample transport
• Pick a suitable container
• Keep samples cool, no warming or frozing of samples is accepted
• Keep samples in dark.
2.2 Soil samples
By the collection of soil sample, one should keep in mind, that
• every sample shoud characterize a certain type of region or land
• from a certain layer appropriate to a certain depth (topsoil)
• different layers of depth separately
• joint averaged sample
point samples shoud be collected over the whole region
Pick the best one!
Sampling site: A well delimited area, where sampling operations take place Sampling point: The place where sampling occurs within the sampling site To ensure the representativity of soil sample:
Terminology in soil sampling (IUPAC Recommendations 2005)
Transport of soil samples:
no warming or frozing of samples is accepted keep in dark.
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Soil sample pretreatment Washing, drying
Grinding/homogenisation
Biologically active samples should not be exposed to prolonged warming ! Extraction of analyte
o solvent extraction
o ashing and subsequent dissolution o extraction in aqueous solutions Problems:
General contamination with pesticides Internal standard
Reference material Reference materials
A material or substance one or more of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement method or for assigning values to materials
- Pure standards
- Solutions - one analyte - several analytes
- analyte and unwanted constituent - Synthetic mixtures
- Matrix reference materials
2.3 Atmospheric analysis and air sampling - Collection of one specific substance
- Collection of several substances - Solid sample analysis
- Absorption of gases in liquids (special reagents) - Adsorption of substances on solid sorbents
Passive or active sampling devices - Filtration of particles
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Soil sample pretreatment Grinding/homogenisation
Biologically active samples should not be exposed to prolonged warming ! solvent extraction – neutral organic compounds
ashing and subsequent dissolution – elemental composition extraction in aqueous solutions – “available” ions
General contamination with pesticides
A material or substance one or more of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement method or for assigning values to materials
one analyte several analytes
analyte and unwanted constituent Synthetic mixtures
Matrix reference materials – natural – fortified
Atmospheric analysis and air sampling Collection of one specific substance
of several substances Solid sample analysis
Absorption of gases in liquids (special reagents) Adsorption of substances on solid sorbents
Passive or active sampling devices Filtration of particles
11 Biologically active samples should not be exposed to prolonged warming !
A material or substance one or more of whose property values are sufficiently homogeneous and well established to be used for the calibration of an apparatus, the assessment of a measurement method or for assigning values to materials
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3. Titrimetric ja gravimetr
2.1 Titrimetric method
Titrimetry is a method of volumetric analysis.
Titration is a quick, accurate and widely used way of measuring the amount of a substance in solution and is performed by adding an exact volume of a standard solution needed to react with the analyte in the
Thereby a titration reaction References Concentration volume
Equivalence point
The equivalence point or stoichiometric point responds to the stoichimetry of chemical reaction:
the amount of added titrant is chemically equal to the amount of analyte, per moles.
The
change occuring immediate after the equivalence point
if 1 mole
c
cA – molar concentration of the analyte in the sample VT – volume of titrant used during titration up to equivalence point
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ja gravimetric methods
Titrimetric method
Titrimetry is a method of volumetric analysis.
Titration is a quick, accurate and widely used way of measuring the amount of a substance in solution and is performed by adding an exact volume of a standard solution needed to react with the analyte in the sample.
titration reaction between titrant T and analyte A occurs.
References:
Concentration CT, volume VT of titrant
volume of sample V, concentration of analyte C Equivalence point
The equivalence point or stoichiometric point responds to the stoichimetry of chemical reaction:
A + T →→→ C+D →
the amount of added titrant is chemically equal to the amount of analyte, per moles.
The end point is the point in a titration when a physical change occuring immediate after the equivalence point
Calculation of results
le of analyte reacts with 1 mole of titrant
c T V T = c A V
cT - molar concentration of titrant
molar concentration of the analyte in the sample volume of titrant used during titration up to equivalence point
V - sample volume
12 Titration is a quick, accurate and widely used way of measuring the amount of a substance in solution and is performed by adding an exact volume of a standard
occurs.
CA
The equivalence point or stoichiometric point responds to the
the amount of added titrant is chemically equal to the amount is the point in a titration when a physical change occuring immediate after the equivalence point
volume of titrant used during titration up to equivalence point
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The equivalence point can be determined by
• precipitation
• pH
• potentiometry
• conductance
• isothermal titration calorimeter
• thermometric analysis.
Requirements for successful titration
the reaction should be stoichiometric, there should be a the number of moles in reaction
rapid rate of reaction
end point and equivalence point should coincide
other components of a sample should not alter the stoichiometry of the reaction.
2.2 Methods of titrimetry
Direct titration
Determination of equivalence point or nd point by physical changes:
occurence or disappearing of precipitate occurence or disappearing of colour
change of colour.
What kind of titration terror can not be avoided?
Backtitration - if the reaction is then
• measured volume if titrant is added in excess (compared to theoretically needed amount)
• excess titrant is back Substitution titration
• sample should contains stronger
• sample is titrated with agent
• the volume of weaker chelating agent that separates is determined
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equivalence point can be determined by or with
isothermal titration calorimeter analysis.
Requirements for successful titration:
the reaction should be stoichiometric, there should be a definite ratio between the number of moles in reaction
rapid rate of reaction
end point and equivalence point should coincide
other components of a sample should not alter the stoichiometry of the
Methods of titrimetry
ination of equivalence point or nd point by occurence or disappearing of precipitate occurence or disappearing of colour change of colour.
What kind of titration terror can not be avoided?
if the reaction is slow or determination of end point is complicated measured volume if titrant is added in excess (compared to theoretically
is back-titrated with a regent
sample should contains stronger chelating agent
sample is titrated with the reaction produkt of titrant and weaker the volume of weaker chelating agent that separates is determined
13 definite ratio between
other components of a sample should not alter the stoichiometry of the
slow or determination of end point is complicated, measured volume if titrant is added in excess (compared to theoretically
weaker chelating the volume of weaker chelating agent that separates is determined
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Potentiometric titration
http://www.postech.ac.kr/class/chem241/0129
Calculation of results
Conductivity of a solution depends on the ions that are present in it. During many titrations, the conductivity changes significantly
Isothermal titration calorimeter uses the heat produced or consumed by the reaction to determine the endpoint.
Thermometric - heat of the reaction is measured and the end point is determined by the rate of temperature change
2.2.1 Applications o Acid-base titration
analyte and an acidic or basic titrant.
Applicable for the determination of alkallinity, that is the capacity of water sample to accept H
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Potentiometric titration
http://www.postech.ac.kr/class/chem241/0129-1.jpg
potential between strandard electrode and working electrode changes suddenly as the
equivalence point is reached
exact method
suitable for turbid solutions relatively low selectivity
(determined by the selectivity of the reaction)
labor-consuming slow
of a solution depends on the ions that are present in it. During many titrations, the conductivity changes significantly.
calorimeter uses the heat produced or consumed by the reaction to determine the endpoint.
heat of the reaction is measured and the end point is determined by the rate of temperature change.
Applications for environmental analysis
base titration - is based on the neutralization reaction between the analyte and an acidic or basic titrant.
Applicable for the determination of alkallinity, that is the capacity of water H+ ions
14 potential between strandard
electrode and working electrode changes suddenly as the
equivalence point is reached
for turbid solutions relatively low selectivity
the selectivity of
of a solution depends on the ions that are present in it. During many
calorimeter uses the heat produced or consumed by the reaction
heat of the reaction is measured and the end point is determined by
is based on the neutralization reaction between the Applicable for the determination of alkallinity, that is the capacity of water
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Alkalinity in excess alkaline earth metal concentrations is significant in determining the suitability of a water for irrigation. Alkalinity measurements are used in the interpretation and control of water and wastewater treatment processes. Raw domestic wastewater has an alkalinity less than, or only slightly greater that, that of the water supply!
Alkalinity serves as a pH buffer and reservoir for inorganic carbon. Basic species responsible for alkalinity :
CO2+ H2O → HCO CO32- +H+ → HCO OH- + H+ →H2O
Alkalinity is titrated with different indicators:
• phenolphthalein
• general – up to pH 4,3 (methylorange).
o Precipitation titration
For example for the determination of chlorides (titrant AgNO3)
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Alkalinity of water is its acid-neutralizing capacity. It is the sum of all the titratable bases. The measured value may vary significantly with the end-point pH used.
Alkalinity is a measure of an aggregate property of water and can be interpreted in s of specific substances only when the chemical composition of the sample is
Alkalinity is a measure of an aggregate property of water and can be interpreted in s of specific substances only when the chemical composition of the sample is